1. Field of the Invention
The present invention relates to transfer of progressive scan digital television data (DTV) with non-tearing, and more particularly to a method and apparatus for transferring progressive scan DTV data on a peripheral component interconnect (PCI) bus with non-tearing.
2. Description of the Related Art
The advent of digital television technology has presented significant opportunities for the computer industry. Computer systems are expected by many to join traditional consumer television products as mainstream devices for receiving digital television (DTV) signals. A DTV-enabled computer system will likely include a DTV receiver for receiving DTV data signals.
Conventional computer system video architecture for supporting analog television data has offered certain system limitations for a computer system DTV architecture. Typically, the graphics video port in computer system video architecture has not been a standard port. It has thus been configured to support a number of proprietary port types. Both a non-standard graphics controller port and a video port cable have been required to accommodate analog television data. This has compromised refresh rate speed and analog television data resolution.
A common, recurring problem with analog television data in these situations has been what is known as tearing. It occurred because of different refresh rates between the graphics controller and the incoming data. At times, portions of two separate data frames were displayed rather than a single whole frame. The display image thus appeared torn. Because of this, the problem was known as tearing. So far as is known, it was typical to force the graphics controller refresh rate to match the incoming video refresh rate, a technique known as genlocking. This, however, had problems. Usage of the display screen was less than optimal. Also, there was often an undesirable, noticeable flicker on the display screen.